CVE-2026-98236 — net: wwan: mhi_wwan_mbim: check skb_copy_bits() return value
In the Linux kernel, the following vulnerability has been resolved: net: wwan: mhi_wwan_mbim: check skb_copy_bits() return value mhi_mbim_rx() ignores the return value of skb_copy_bits() when it copies each datagram out of the NTB. The datagram offset and length come from the DPE, which is only checked to lie within the NTB itself, so a modem can point a datagram outside the received skb. The copy then fails and the freshly allocated skbn is passed to netif_rx() with its uninitialized contents still in place, leaking kernel heap memory into the network stack. Free the skb and account an error when the copy fails. Verified in a QEMU guest with a fault injector pointing a DPE outside the received NTB: the copy fails, and the unpatched driver hands the uninitialized skbn to the network stack (observed as "unknown protocol" on bytes that were never written). With this check the failed datagram is dropped and counted as an rx error. Changes in v2: factor the free-and-count sequence out into mhi_mbim_rx_drop(), shared with the unknown-protocol path, as suggested by Loic Poulain.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ aa730a9905b7b079ef2fffdab7f15dbb842f5c7c and < 650af68435eaee783824457d2ef78cc5c03c1e88≥ aa730a9905b7b079ef2fffdab7f15dbb842f5c7c and < 350fd3125ee26b5243935fd9e2b4d162ffba430a≥ aa730a9905b7b079ef2fffdab7f15dbb842f5c7c and < dd136f1fdd1059f3bc25ede3a8def8f0ee151ce7≥ aa730a9905b7b079ef2fffdab7f15dbb842f5c7c and < 298659c3677bf622afa9d77549cb4a967f9541e9≥ aa730a9905b7b079ef2fffdab7f15dbb842f5c7c and < 02eba5f36d20283f144f75d47f0354a85e4f78f0≥ aa730a9905b7b079ef2fffdab7f15dbb842f5c7c and < 7e98216e9da08b79e07a514d2a4f7646f8c9ccb9≥ aa730a9905b7b079ef2fffdab7f15dbb842f5c7c and < 31550d585589fde1ae95bf7f7a8188b2d2fdf1c7version 5.15 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.18%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
7 on the record
- git.kernel.org/stable/c/350fd3125ee26b5243935fd9e2b4d162ffba430a
- git.kernel.org/stable/c/31550d585589fde1ae95bf7f7a8188b2d2fdf1c7
- git.kernel.org/stable/c/02eba5f36d20283f144f75d47f0354a85e4f78f0
- git.kernel.org/stable/c/dd136f1fdd1059f3bc25ede3a8def8f0ee151ce7
- git.kernel.org/stable/c/7e98216e9da08b79e07a514d2a4f7646f8c9ccb9
- git.kernel.org/stable/c/650af68435eaee783824457d2ef78cc5c03c1e88
- git.kernel.org/stable/c/298659c3677bf622afa9d77549cb4a967f9541e9
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 14h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 14h
- Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
- Unknown CVE-2026-98428 ALSA: usb: 6fire: Avoid embedded URBs 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-98236 is "net: wwan: mhi_wwan_mbim: check skb_copy_bits() return value", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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